Call $x$ the result of the first dice and $y$ the result of the second dice after they are thrown, let $z=2x+y$. How can I make a probability distribution corresponding to $z$ using $d_1$ and $d_2$ ? I tried adding them

$\begingroup$Just as a tiny comment: it would be better to first evaluate: ee = PDF[tf, x], and then DiscretePlot[ee {x, 2, 12}] . By contrast, DiscretePlot[PDF[tf, x], {x, 2, 12}] might take about 100 times longer to plot, because it tells Mma to calculate PDF[t,x] at each value of x (rather than just solving it once).$\endgroup$
– wolfiesNov 28 '15 at 17:37

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